In a network device, a forwarding chip, e.g. an application specific integrated circuit (ASIC) chip may fast forward data packets based on maintained forwarding entries, such as Address Resolution Protocol (ARP) entries, Forwarding Information Base (FIB) entries, and Media Access Control (MAC) entries etc.
By using server virtualization technologies, a physical server can host multiple Virtual Machines (VMs). Each VM has its own Virtual Network Interface Card (VNIC), IP address and MAC address.
When a network device of a data center (e.g. a layer-three switch) sends data packet to the VM for the first time, the network device learns the MAC address of the VM based on the ARP protocol, generates an ARP entry and a host route, and stores the generated ARP entry and the host route in a physical forwarding chip of the network device.
Along with the increasing of the VMs, the number of the ARP entries and the host routes stored in the physical forwarding chip of the network device is increased. Generally, the number of entries supported by the physical forwarding chip is limited. When entry resources of the physical forwarding chip of the network device are occupied by large numbers of route entries, some forwarding application requirements cannot be satisfied by the network device.